GENEVA, May 14 (Reuters) - Aid agencies in Libya called on Tuesday for a U.N. resolution to support people caught in fighting around Tripoli, where the United Nations says 66,000 people have been forced out of their homes and at least 454 killed since early April.

Forces loyal to Libya’s government are defending the capital against an offensive by the Libyan National Army (LNA) led by Khalifa Haftar, who accuses the administration of being controlled by terrorists, a charge it denies.

Haftar is supported by Egypt and the United Arab Emirates but denounced by internationally-recognised Prime Minister Fayez Serraj as an “aspiring military dictator”.

As well as uprooting thousands of Libyans, Haftar’s campaign has added to the hardship faced by thousands of migrants who use Libya’s western coast to set off on perilous sea journeys to Europe.

A report on migrants and displaced people by the “Protection Sector” group of aid agencies, which is coordinated by the U.N. refugee agency UNHCR, said 3,000 migrants remained trapped in detention centres close to areas of fighting, and the use of medium and heavy weapons in populated areas continued unabated.

“The U.N. Security Council should adopt a resolution calling for the protection of civilians and accountability for serious violations of international human rights and humanitarian law,” the Protection Sector said.

It said the European Union should stop hampering search and rescue in the Mediterranean, ensure that anyone rescued can go to a safe port as required by international law, and stop supporting Libya’s use of detention centres until standards in those facilities improved.

Last week a migrant boat capsized, killing 59 people, and since the Tripoli clashes began, 871 migrants have been picked up and returned to detention in often unacceptable conditions, according to the U.N. migration agency.

Charlie Yaxley, a UNHCR spokesman, said nobody should be returned to Libya and returning people there could not be considered a “rescue”.

In Tripoli, the U.N.-backed government said shelter has been provided to 70,000 displaced people.

Hotels and resorts have been mobilised to receive the displaced, the head of the government Emergency Committee, Othman Abduljaleel, told official Al-Rasmiya TV channel.

Meanwhile, exchanges of gunfire and rockets continued but there were no changes to the frontlines around the capital.

On Tuesday, a rocket hit Qaser Ben Ghashir, an area in southern Tripoli controlled by forces loyal to Haftar, killing at least two people, a local witness told Reuters. (Reporting by Tom Miles Additional reporting by Ahmed Elumami Editing by William Maclean and Frances Kerry)